Power transmission



Dec. 1, 1942.

E. L. RosE POWER TRANSMISSION Original Filed March 28. 1936 INVENTOR l..ROSE Ri/Afm.

ATTORNEY EDWIN Patented Dec. 1, 194.2

Edwin L. Bose, Woodbury, Conn.

original application Much 2s, 1936, semina;

71,419. Divided and this application November ze, 1940,serialtrazas-1,823w l s claims. (ci. s-.162) Y on une .5 5 of Figure 1snowing the parts 1n This invention relates to power transmissionsparticularly to those of the type comprising two or more duid pressureenergy translating devices, one of which Amay function as a pump andanother as a fluid motor.

The present application is a division of copending application SerialNo. 71,419, filed March 28, 193$, now Patent No. 2,236,489.

The invention is particularly concerned with an improved displacementregulator for a variable displacement pump and which is particularlyadapted for the .control of a hydraulic power transmission system fordriving an airplane crane winch of the type which provides for constanttension operation preliminary to picking a floating plane oli from thewater. It will be understood that the present control mechanism,although it is described in connection with such use, is also adaptedfor many other purposes where the control 'of pump displacement isrequired to be made selectively responsive either to'` the pump deliverypressure or to a manual controlling member.

It is an object of the present invention to provide a control devicefor-avariable displacement pump in which the displacement may be variedeither in response to working pressure to maintain a substantiallyconstant pressure or may be controlled to maintain the pressure above apredetermined minimum and to provide manual control means forAselectively transferring the control fromone condition to the other. l Afurther object is to provide a control device of the character describedwherein the pump displacement may be varied selectively either 'inresponse to pressure or may be varied by means one position.

Figure 6 is a view corresponding to Figure 5 showing the parts in asecondposition. l

`Figure 7-is a view corresponding to Figure 5 showing the parts in athird position.

Figure 8 is a fragmentary cross section taken online 8-8 of Figure 1. A

Referring now to Figure 1, thepump generally designated I0 isprovided'with a tilting box I2 mounted upon the usual horiaontaltrunnions for tilting movement to vary the displacement of the pump andthedirection of fluidy delivery. 'Ihe usual rotating .drive shaft,universal joint, socket rings, connecting rods, pistons. and cylinderbarrel constitute the customary revolving group generally designated asI4 and representing the conventional internal construction ot the mentpump.

Referring now to Figures 1 through 8, inclusive, the control mechanismfor the pump I8 is illustrated. The tilting box I2 carries an operatingstud I8 to which is connected by means of. a sliding and pivoting jointI8 a vertically slidable well-known Waterbury -tile of variabledisplaceoperating stem 28. AThe lower end of the stem 28 is formed witha piston 22 slidable in a cylinder bore 28 which is in communicationwith the 20 is formed with a shoulder 28 against which of a manualcontrol mechanism independently Figure 1 is a fragmentary sectional viewof a pump and control mechanism incorporating a preferredV form of thepresent invention.

Figure 2 is a fragmentary sectional view of a latch mechanism taken online 2-2 of Figure l. Figure 3 is a fragmentary sectional view-takenOnline 3-3 of Figure 2.

Figure 4 isa fragmentary sectional view taken on line 4-4 of Figure 2.

` Figure 5 is a fragmentary sectional view taken 55 a spring plate 38abuts. Aspring 82 has its lower end abutting the spring plate 38 and itsupper,

end abutting a spring platev 34 adjustably se' cured to the pump casing.The stem 20 projects through the spring plate 88 and carries two sets ofvyieldablev latches 38 and 38 (see Figs. 2, 3 and 4). The latches 88 and38 are disposed at .right angles t0 one another and vertically lspacedso that the latches 8B may engage the upper side of ya ledge '88 whilethe latches 38 may engage the lower side thereof. The ledge 40 is formedintegrally with a tubular 'member 82, the outside Aof which is screwthreaded for engagement with' an interiorly threaded sleeve 44.

The tubular member -42 carries an upwardly projecting stem 48 having anoperating handle 48 at its upper end. The stem 46 is formed with threelongitudinal grooves 50 by which it'may be locked in any one of threeangularly spaced positions by means of a spring-pressed, manuallykoperable detent '52. The sleeve 44 carries a bevel gear 54 at its upperend which meshes with a bevel gear 58 carried by a shaft 58 which may beoperated by a hand wheel 8 8. ,A flange 82 which is rotatably mountedbetween a supporting sleeve 66 and a cover member 88 restrains thesleeve 44 against vertical movement.

The ledge 40 is interrupted at points 18 and 12 (see Fig. 8) in order topermit the latches 36 5 and 38 to pass the ledge'in either direction ofmovementin certain positions of the operating handle 48. Thus, in theposition illustrated in Figure 5 which may be called the Vconstanttension position, both the latches 36 and 38 are op- 10 posite theportions l0 and 12, respectively, so that the stem' 20 may reciprocatefreely through its full range` of move nent. In the position illustratedin Figure 6 lhich may be termed the manual control position, both thelatches 36 and 15 38 are opposite portions of the ledge 40 so that thetubular member 42 may be rigidly secured to the stem 20. In the positionillustrated .in Figures '7 and 8 which may be termed the pickupposition, the interrupted portions 10 are in 20 register with thelatches 36 While portions of the ledge 4U are in register with thelatches 38. In this position the stem 20, after it has once moved thelatches'38 downwardly past the ledge 40, is prevented from moving'upwardly again 25 beyondthe point where the latches 38 engagethe bottomof the ledge 40 although the stem 20 is free to move downwardly fromthis position at any time.

It will be seen that lin the constant tension position of the handle 48,the position of the tilting box I2 is under the sole control of thepiston 22 and the spring 32. In the manual control position of. thehandle 48, the position 'of the tilting box l2 once the latches 36 and38 35 have been engaged with the ledge 40 is under the sole control ofthe hand wheel 60. In the pick-up position the movement of the tiltingbox upwardly is limited by the position of the ledge 40 so long as theworking pressure of the pump 40 Iis suflicient to overcome the force ofthe spring 32 and hold the latches 38 in engagement with 'the ledge 40.Upon a drop in pressure below this point, the position of the tiltingbox is determined by the pressure through the medium f 4.; the piston 22and the spring 32.

It will be noted that if the handle 48 is turned from constant tensionposition to pick-up position at an instant when 'the latches 38 areabove the ledge 40 that the tilting box remains under tu' the control ofthe piston 22 and spring 32 until such time as the stem 20 has; moveddownwardly to bring the latches 38 beneath the ledge 40 and h'as againstarted upwardly to engage the latches 38 with the ledge 48. y

While the form vof embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be vunderstood that other formsmight b'e adopted, all coming within the scope of the claims whichfollow.

What is claimed isas follows:

1. A control device for a variable displacement pump comprising incombination means for varying th'e displacement .of the pump, automaticmeans responsive to the working pressure in the 65 pump for operatingthe displacement varying means, means for limiting the operation of theautomatic means to a selected displacement range, manually operablemeans for selectively rendering the limiting means effective orineffective, I and additional means for operating the displacementvarying means independently of the working pressureof the pump.

2. A control device for a variable displacement pump comprising incombination means for 76 varying the displacement of the pump, automaticmeans responsive to the working pressure in the pump for operating thedisplacement varying means, means for hunting the operation of theautomatic means to a selected displacement range, Amanually operablemeans for selectively rendering the limiting means .eiective or inef-.ing pressure in the pump for operating the displacement varying means,means including a stop engageable with said member ior limiting theoperation of the automatic means to a selected displacement range,manually operable means for selectively rendering the limiting meanseffective vor ineffective, and additional means for operating thedisplacement varying means through said stop.

4. A control device for a variable displacement` pump comprising incombination, a movableA member for varying 'the displacement of thepump, automatic means responsive to the working pressure in the pump foroperating the dl'splacement varying means, means including a stopengageable with said member for limiting the operation of the automaticmeans to a selected displacement range, manually operable means forselectively rendering the limiting means effective or ineiective, andadditional means for operating the displacement varying means throughsaidstop independently of the working pressure of the pump, saidlast-named means including mechanism operable to vary the range ofdisplacement through which the automatic means is operable when thelimiting means is eiective. I

5. A control device for a variable displacement pump comprising incombination a movable member for varying the displacement. of the pump,automatic means responsive to the working pressure in the pump foroperating the displacement varying means, means including a latchmechanism and a keeper mechanism, one

of which'is carried by the member and the other of whichis engageablewith the one carried by its full range after the last means is shiftedto a range-limiting position and until it moves into the limited rangeunder the action ofthe automatic means.

6. A control device for a variable displacement pump comprising incombination a movable.

member for. varying the displacement of the pump, `automatic meansresponsive to the vvorking pressure in the pump'ior operating thedisplacement'rvarying means, means including a latch, mechanism and akeeper mechanism, one of which is: carried by the member and the otherof which is engageable with the one carried by said member for limitingthev operationl of -`the automatic means to a selected .'lisplacemeutlrange, manually operable means to shift one of said mechanisms intoV andout of the path of the other mechanism on said member, whereby themovable member is free to move throughout its full range after thelast'I means is shifted to a range-limiting position and until it movesinto the limited range under the ,action of the automatic means,l andadditional means for operating the displacement varying means includinga second latch mechanism engageable with said keeper mechanism andcoacting with the rst latch mechanism to provide a rigid connection withthe movable member. t

EDWIN L. ROSE

